package com.travelzen._8.polymorphic.xiebian;

public class CovariantReturn {
	public static void main(String[] args) {
		Mill m = new Mill();
		Grain g = m.process();
		System.out.println(g);
		m = new WheatMill();
		g = m.process();
		System.out.println(g);
	}
}
